Okay, lets start from the top and work our way in
Firstly, You can expect exhaust manifolds to run you about 200 bucks. Travis at www.hulkspeed.com
is working on Series 1 prototypes for my car (a 95 SSEi). Once he gets the prototype ready, he'll be prepared to sell them.
That being said, there are others here who have done it themselves.
Exhaust manifold thread here.
As for throttle bodies, again the same genius here (hehe) has switched from a Gen 2 (92/93) to a Gen 3 (94/95) Supercharger and throttle body. Those have a wider inlet among other improvements. This switch isn't for the faint of heart though. Willwren'* super experienced with this stuff, plus he has a spare car to drive while he'* busy experimenting with his 93.
Supercharger Stuff here.
Regarding chip: Jet chip (http://www.jetchip.com/
) sells a chip that a number of 1993 owners use on the club.
There'* A LOT more to this whole thing and you really need to wait on the more experienced 1993 owners to speak up, but I hope that reading gets you moving in the right direction.